Violation ID |
Occurred Date |
Violation Type |
(-) Violation Description |
Corrective Action |
Status |
Classification |
Source |
1131126 |
05/31/2024 |
DMON |
Discharger did not monitor effluent acute toxicity during May as required. |
|
Violation |
B |
Report |
1123471 |
12/31/2023 |
CAT1 |
Ammonia, Total (as N) Monthly Average limit is 31 mg/L and reported value was 33 mg/L at EFF-003. |
Staff has coordinated de watering efforts to minimize ammonia productions. |
Violation |
B |
eSMR |
1122071 |
09/07/2023 |
ATOX |
Acute Toxicity Instantaneous Minimum limit is 70 % survival and reported value was 50 % survival at EFF-003. |
|
Violation |
A |
Report |
1116056 |
03/01/2023 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 240 MPN/100 mL at EFF-003. |
staff performed cleaning of secondary clarifies and contact channels |
Violation |
B |
eSMR |
1115096 |
02/10/2023 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 86 MPN/100 mL at EFF-003. |
Contact channel drained and cleaned. |
Violation |
B |
eSMR |
1115095 |
02/01/2023 |
OEV |
Total Coliform 7-Day Median limit is 23.0 MPN/100 mL and reported value was 55.0 MPN/100 mL at EFF-003. |
Contact channel drained and cleaned. |
Violation |
B |
eSMR |
1114066 |
01/09/2023 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 31 MPN/100 mL at EFF-001. |
On 1/9/23, we exceeded our final effluent coliform limit of 23 MPN per 100 mL as a 7-day median. Our 7-day median was 31.0. Corrective action: Staff cleaned and hosed down the chlorine contact basin walls. |
Violation |
B |
eSMR |
1109558 |
09/17/2022 |
CAT1 |
Settleable Solids Daily Maximum limit is 0.2 ml/L and reported value was 0.4 ml/L at EFF-001. |
Adjusted plant process |
Violation |
B |
eSMR |
1108803 |
08/31/2022 |
OEV |
pH Instantaneous Minimum limit is 6.5 SU and reported value was 6.2 SU at EFF-001. |
Additional training and review of contact channel cleaning procedures. In addition, updating current contact cleaning standard operation procedure. |
Violation |
B |
eSMR |
1108802 |
08/13/2022 |
CAT1 |
Settleable Solids Maximum Daily (MDEL) limit is 0.2 ml/L and reported value was 0.4 ml/L at EFF-001. |
Adjusted plant process |
Violation |
B |
eSMR |
1108804 |
08/03/2022 |
ATOX |
Acute Toxicity-Fathead Minnow-survival 3-Sample Median limit is 90.0 % survival and reported value was 59 % survival at EFF-001. *** MMP Exempt Reason:WDRs contain effluent limitations for toxic pollutants. |
Optimizing de-watering process to limit the amount of ammonia generated at the plant. |
Violation |
A |
eSMR |
1108805 |
08/03/2022 |
ATOX |
Acute Toxicity-Fathead Minnow-survival Instantaneous Minimum limit is 70.0 % survival and reported value was 25.0 % survival at EFF-001. *** MMP Exempt Reason:WDRs contain effluent limitations for toxic pollutants. |
Optimizing de-watering process to limit the amount of ammonia generated at the plant. |
Violation |
A |
eSMR |
1106584 |
06/01/2022 |
ATOX |
Acute Toxicity-Fathead Minnow-survival Instantaneous Minimum limit is 70.0 % survival and reported value was 52 % survival at EFF-001. *** MMP Exempt Reason:WDRs contain effluent limitations for toxic pollutants. |
Adjusted plant process control |
Violation |
A |
eSMR |
1102692 |
02/09/2022 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 28 MPN/100 mL at EFF-001. |
Chlorine Contact channels were cleaned. |
Violation |
B |
eSMR |
1102691 |
02/07/2022 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 33 MPN/100 mL at EFF-001. |
Chlorine Contact channels were cleaned. |
Violation |
B |
eSMR |
1102693 |
02/02/2022 |
CAT1 |
Settleable Solids Maximum Daily (MDEL) limit is 0.2 ml/L and reported value was 0.3 ml/L at EFF-001. |
Process control adjustments were made to improve floculation and clarity of supernatant leaving the secondary clarifiers. In addition, the secondary clarifiers were also cleaned. |
Violation |
B |
eSMR |
1101293 |
01/14/2022 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 49 MPN/100 mL at EFF-001. |
Cleaned dechlorination and east contact basins |
Violation |
B |
eSMR |
1101296 |
01/12/2022 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 49 MPN/100 mL at EFF-001. |
Cleaned dechlorination and east contact basins |
Violation |
B |
eSMR |
1101295 |
01/10/2022 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 49 MPN/100 mL at EFF-001. |
Cleaned dechlorination and east contact basins |
Violation |
B |
eSMR |
1101294 |
01/07/2022 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 49 MPN/100 mL at EFF-001. |
Cleaned dechlorination and east contact basins |
Violation |
B |
eSMR |
1091453 |
05/31/2021 |
CAT1 |
Ammonia, Total (as N) Monthly Average limit is 31 mg/L and reported value was 34 mg/L at EFF-001. |
The City is actively pursuing ideas to lower ammonia levels in the Effluent. Operations staff has been utilizing a Rotary Drum Thickener (RDT) to reduce gallons of Primary Sludge to the digester. The reduction in sludge, in theory, should reduce loading to the digester reducing dewatering. The operations staff is continuously evaluating and adjusting dewatering operations. |
Violation |
B |
eSMR |
1091452 |
05/05/2021 |
ATOX |
Acute Toxicity-Fathead Minnow-survival Instantaneous Minimum limit is 70 % survival and reported value was 35 % survival at EFF-001. |
Yuba City Cleaned out the dichlorination channel in response to the bioassay test results. |
Violation |
A |
eSMR |
1090608 |
04/26/2021 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 27 MPN/100 mL at EFF-001. |
In response to these exceedances, we raised the chlorine set point. |
Violation |
B |
eSMR |
1090609 |
04/23/2021 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 27 MPN/100 mL at EFF-001. |
In response to these exceedances, we raised the chlorine set point. |
Violation |
B |
eSMR |
1085161 |
12/31/2020 |
CAT1 |
Ammonia, Total (as N) Monthly Average (Mean) limit is 31 mg/L and reported value was 33 mg/L at EFF-002. |
The City is actively pursuing ideas to lower ammonia levels in the Effluent. Staff is currently evaluating and adjusting dewatering operations. |
Violation |
B |
eSMR |
1083362 |
11/18/2020 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 26 MPN/100 mL at EFF-002. |
In response to these exceedances, we drained and cleaned the West Contact Basin Channel on November 30, 2020. Chlorine analyzers were recalibrated on November 30, 2020. |
Violation |
B |
eSMR |
1083361 |
11/04/2020 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 52 MPN/100 mL at EFF-002. |
In response to these exceedances, we drained and cleaned the West Contact Basin Channel on November 30, 2020. Chlorine analyzers were recalibrated on November 30, 2020. |
Violation |
B |
eSMR |
1083360 |
11/02/2020 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 37 MPN/100 mL at EFF-002. |
In response to these exceedances, we drained and cleaned the West Contact Basin Channel on November 30, 2020. Chlorine analyzers were recalibrated on November 30, 2020 |
Violation |
B |
eSMR |
1081778 |
10/30/2020 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 70 MPN/100 mL at EFF-002. |
In response to this exceedances, we recalibrated our chlorine analyzers. Throughout this period, the City was discharging to the Ponds, Effluent Discharge Point 002. |
Violation |
B |
eSMR |
1082751 |
08/15/2020 |
DMON |
Turbidity samples for RSW-001 and RSW-002 were analyzed outside of holding time. |
|
Violation |
B |
Report |
1078802 |
07/01/2020 |
ATOX |
Acute Toxicity-Fathead Minnow-survival Instantaneous Minimum limit is 70 % survival and reported value was 0 % survival at EFF-001. *** MMP Exempt Reason:CWC section 13385(i)(1)(D) -- WDRs contain pollutant-specific effluent limitations for toxic pollutants. |
The digester rehabilitation project was completed on July 15th, 2020. The completion of this project should decrease dewatering operations, thus lowering ammonia to the headworks. |
Violation |
A |
eSMR |
1076463 |
05/31/2020 |
CAT1 |
Ammonia, Total (as N) Monthly Average (Mean) limit is 31 mg/L and reported value was 33 mg/L at EFF-001. |
The Digester rehabilitation project is scheduled to be completed in July of 2020. The completion of this project would decrease dewatering operations. Staff is currently evaluating and adjusting process options during this digester rehabilitation project. |
Violation |
B |
eSMR |
1074991 |
04/30/2020 |
CAT1 |
Ammonia, Total (as N) Monthly Average (Mean) limit is 31 mg/L and reported value was 36 mg/L at EFF-001. |
During the Month of April 2020, our East Digester was offline. The East digester is undergoing a cover replacement changing from a floating to a fixed cover. The higher sludge flows processed by our belt press produced extra ammonia in our return flow, adding significantly to the influent ammonia load.
The Digester rehabilitation project is schedule to be completed in July of 2020. The completion of this project would decrease dewatering operations. Staff is currently evaluating and adjusting process options during this digester rehabilitation project. |
Violation |
B |
eSMR |
1072117 |
02/29/2020 |
CAT1 |
Ammonia, Total (as N) Monthly Average (Mean) limit is 31 mg/L and reported value was 32 mg/L at EFF-001. |
During the month of February 2020, we drained our East digester to prepare for changing from a floating to a fixed cover. The extra digested sludge processed by our belt press produced extra ammonia in our return flow adding significantly to the influent ammonia load. |
Violation |
B |
eSMR |
1070141 |
12/13/2019 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 94 MPN/100 mL at EFF-002. |
On December 16th, 2019, we drained and deep cleaned our chlorine contact basin. |
Violation |
B |
eSMR |
1067145 |
10/28/2019 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 56 MPN/100 mL at EFF-002. |
In response to the violation, we recalibrated our chlorine analyzers and increased the chlorine dose setpoint. |
Violation |
B |
eSMR |
1067146 |
10/23/2019 |
OEV |
Total Coliform 7-Day Median limit is 23 MPN/100 mL and reported value was 79 MPN/100 mL at EFF-002. |
In response to the violation, we recalibrated our chlorine analyzers and increased the chlorine dose setpoint. |
Violation |
B |
eSMR |
Report displays most recent five years of violations. Refer to the Interactive Violation Report for more data.
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